The primary objective of this research is to obtain three-dimensional crystals of bovine rhodopsin, and to collect initial low-resolution crystallographic data from these crystals. To accomplish this, bovine rhodopsin will be isolated and purified using modifications of previously described procedures. Several thousand crystallization conditions will be screened using preparations of solvents (at specific pH and temperature) containing variable amounts of detergents, precipitating agents, and protein. Screening for optimum crystallization conditions will be carried out under infrared light using two basic crystallization methods: vapor diffusion and microdialysis. The experiments will be stored in light tight vessels and examined using infrared light. If crystals of suitable quality are obtained from this pilot study, future studies will include the collection of high-resolution X-ray data from which the complete three-dimensional molecular structure of the protein will be obtained. The crystal structure will provide a great deal of information about the mechanistic action and biological function of rhodopsin.